In‐situ groundwater remediation is usually limited by the incomplete mixing of reactive species due to creeping flow characteristics and limited dispersion in porous media. In this study, we propose a novel approach to deliver chemicals through a multi‐screen well (MSW) to enhance the in‐situ remediation efficiency without extra energy or labor costs. The basic idea is to separate the injected solution into several plumes to enlarge the contact area between injected chemical compounds and ambient contaminants and enhance the mass exchange flux and reactive mixing. We perform laboratory experiments and numerical simulations of steady‐state instantaneous reactive transport in two‐dimensional porous media. We consider three separate screens in an MSW for the injection of treatment solutions and compare its plume distributions with a classical single‐screen well system. The experimental results confirm our conjecture and demonstrate the reliability of the numerical model. Furthermore, we derive an optimal injection interval of the MSW system by comparing analytical and numerical methods and demonstrate its capability to achieve effective transverse mixing and reaction enhancement. An interval that is smaller than the optimal injection interval leads to the exhaustion of contaminants between the injected plumes and the coalescence of the separate injected plumes at the downgradient portion along the travel distance, which reduces the effectiveness of the MSW system. We also investigate the sensitivity of the injected concentration, individual screen length, transverse dispersivity, and seepage rate on the determination of the optimal injection interval and provide suggestions about the design of an MSW system.

中文翻译：

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通过多筛孔有效地输送化学物质，以增强多孔介质中溶质柱的混合和反应

由于蠕变流动特性和在多孔介质中的分散性有限，原位地下水修复通常受到反应性物质不完全混合的限制。在这项研究中，我们提出了一种通过多筛孔（MSW）输送化学品的新颖方法，以提高原位修复效率，而无需额外的能源或人工成本。基本思想是将注入的溶液分成几个羽状流，以扩大注入的化合物与环境污染物之间的接触面积，并增强质量交换通量和反应混合。我们在二维多孔介质中进行稳态瞬时反应传输的实验室实验和数值模拟。我们考虑了MSW中用于处理溶液注入的三个独立滤网，并将其羽流分布与经典的单滤井系统进行了比较。实验结果证实了我们的猜想并证明了数值模型的可靠性。此外，我们通过比较分析和数值方法得出了MSW系统的最佳注入间隔，并证明了其实现有效横向混合和反应增强的能力。小于最佳注入间隔的间隔会导致注入羽流之间的污染物耗尽，并且沿着行进距离在降梯度部分处的单独注入羽流会聚结，从而降低了MSW系统的效率。我们还研究了注入浓度的敏感性，